Hypodermic syringe



K lgtented Nov. *A8, 1927., V

warren s.

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nronnnivrrcsrnrnen.

'Application 'filed March 13, 1926. lSveria'lljNo. 94,579:

'My' invention relates' to a hypodermic syringe, and more particularly to the gen-2 eral type disclosedin myco-pending application Serial` N o.- 67`,144, filed `November 5,

1925,' in` which a tapered needle: carrier is held frictionally in a tapered portion ofthe barrel iropening, the piston lbeing removable from` thief-barrel to permit*` insertion of a needle carrierthrough the barrel.

T'hfefobject of the invention 1s to providel a simplified,v economical, and practicable; mea-ns for looseningithe needlecarrier'infthe.

barrel `when desirable'to'remove the same.

Inr a merel-particular aspect, the' invention has lfor its purposewtoemploy-the piston to loosen the needle carrier fromvthe barrel,I

this resultbeing preferably accomplished by' the provisionvofzinterlocking means between the piston and needlecarrierfsuch thatywhen the piston is turned,the: needlefcarrier is likewise turned within; the:f tapered portion of the barrel and thereby loosened.; i l

To! ,thesel- .'ends, the invention consists in the construction and arrangement of parts that will appear clearly fromkthe following.

description when read in conjunctionV with the accompanying drawing, the novel features being pointed out in the claims following the description.

In the drawing:

Figure 1 is4 a side elevation, partly in section, of a hypodermic syringe incorporating a preferred embodiment of the invention, the piston appearing in normal position at the end of its stroke; f

Figure 2 is an enlarged sectional view, partially broken away, and showing the pisc ton in interlocking engagement with `the needle carrier, and

s Figure 3 is a perspective view of the innerl end of the needle carrier.

.Referring more particularly to the drawing in which like reference numerals refer to corresponding parts throughout the sev-` eral views, l designates the barrel, 2 is the tapered needle carrier held frictionally in a correspondingly tapered portion at the outer end of the barrel opening, and 3 is the piston, all arranged and functioning in the general manner set forth in my aforesaid ap-L plication. i

The needle carrier is positioned within the barrel by inserting it, needle downwardly, into the inner end. after the piston has first been removed. The needle carrier is then permitted to fall to the outer end of the barrel, and the piston' inserted andimoved toward the outerv endrofthe barrel'togive a-x slight blow to the needle carrien w-ithsuijli cient'force so that the latteris held tightly ine place b'yits frictional engagement withV thel tapered vpart ofi the opening; The

syringeis then vready fv r use, after whililj whendesired to removefthe needlecarrier,

- it;;must first .be loosened, andthisil, accom;

plishk through the instrumentalityr `of ,the; pisf; ton, which is turned while in interlocking engagement with the needle carrier.,V i

' Variousfways of effecting this "result are" y possible, and to illustrate the ideaLIghave shown. the needle 'carrier and' piston*V provided onr theiry adjacent ends with,l abutments or lugs 4, and 5, .which are. undercut at'- 6 and 7 respectively. BymovingA the; piston outwardly and turningit .until itsfabutment 4l engages the recess adjacent'to abutment,,5 on 1 the needle carrier, the, ,sailabutmenfts tJin'- terlock.I .on e, 'with' the. ,othenasg shown ,iii Eig`A 'ure-2- .Then.whenf-theypston sfturnedand simultaneously pulled, theneedle carrier 2 is turned with it, and Yat the same time moved inwardly, due to the cooperation of said undercut portions 6 and 7, a very slight turnr ing and pulling movement of the piston be-A ing sut'icient to loosen the needle' carrier from the barrel. The piston is then removed and upon inverting the barrel, the needle carrier will fall therefrom. With this arrangement, it is practicable. to use afresh, sterile needle each time the syringe is used, very little time being required for positioningv and removing the needle carrier. No additional tool is necessary,and the piston, which is always withl the syringe, can be instantly ,manipulated to either 4secure the needle carrier in place frictionally, or eect its removal from the barrel. Y Y

This invention also lends itself to a safer and more sterile operation where a needle is used more than once on the same patient. Ordinarily, after a `needle is used, when the piston is withdrawn to prepare for a second .filling of the needle, any germs or poisonous matter in the needle is sucked back into the` barrel of the syringe and becomes mixed with the fresh solution, greatly endangering .the barrel and eliminate the chance cf suck-v v ing' the' contents of the needlebeck into the barrelz rBefore inserting the new solution,

lthe needlecarrier is tightened again by moving the piston outwardly and tapping the needle carrier with it, which at the same time forces out from theneedleany foreign matter contained therein, and prevents contamination of the fresh solution. .And it is noteworthy that the needle can thus be controlled by a simple and slight manipulation of the piston, and without ever touching the needle or needle carrier.

While the invention has been described with reference to a 'certain particular em'- bodiment, it is not limited to the details herein disclosed, and this application is intended to cover such modifications or departures as may come withinthe intent of the latter `from the barrel, said cooperation taking Vplace while said piston is within the barre i j 2. In a hypodermic syringe', the combination withabarrel having an opening with an inwardly tapering portion, at its `outer end, of a removable tapered needle carrier held frictionally vin said tapered portion of the opening, aV removable piston in the barrel, and meanscarried by the piston engage able with the needle carrier to remove the piston effects turning of the needle carrieritoi loosen the latter for removal from .the barrel.

1 4. In a hypodermic syringe, the-combination with a barrel lhaving an opening with an inwardlyftapering portion at its outer end, of a removable tapered needle'carrier held frictionally in said tapered portion of theopening, a removable piston inthe barrel, and cooperating interlocking abutments on the piston vand needle carrier. whereby turning of' the piston Veffects turning of the needle carrier to loosen the latterV for removal from thel barrel.

In witness whereof," si ed my name.k

I have hereunto FREDERIC J. noFscH'NE'I'DER. 

